The present invention relates to a method and a device for emitting a predetermined series of pulses on an electricity distribution network.
The present invention is initially based on ideas and principles set forth in European Patent Application Publication No. EP 1,136,829, the contents of which are incorporated by reference herein. As set forth in this document, any electric apparatus or element, particularly engines, pumps, transformers, electric bulbs, electric or electronic circuits, relative to its electric supply input, has a complex impedance and generates, when switched on and switched off, a high frequency spurious signal having an electromagnetic origin. As this signal is very short in duration, it is designated, in the present application, as forming a “high frequency spurious pulse” naturally emitted by an electric element.
EP 1,136,829 is based on the fact that such a pulse forms a sort of unique signature representative of a piece of electric apparatus and of its location on the electricity distribution network, enabling it to be differentiated from other electric apparatus. EP 1,136,829 thus provides a method for measuring the electrical power consumption of a piece of electric apparatus connected to an electricity distribution network, wherein the step of detecting the switching on or off of the electric apparatus comprises a step of detecting the high frequency pulse emitted by the apparatus when it is switched on or off, enabling the apparatus to be identified.
EP 1,136,829 also considers, when a piece of electric apparatus only produces a spurious pulse of low amplitude, providing a pulse generator capable of supplying a pulse that replaces the spurious pulse that is too weak. EP 1,136,829 also considers that such a pulse generator can emit a series of pulses comprising a determined number of pulses forming a unique signature, and combining a detection of spurious pulses naturally emitted by certain pieces of apparatus with a detection of the series of pulses emitted artificially by other apparatus equipped with such a pulse generator.
As also indicated in EP 1,136,829, the production of a pulse synthesizer capable of emitting a coded series of pulses having the same appearance as high frequency spurious pulses is, per se, within the understanding of those skilled in the art. One embodiment of such a synthesizer comprises for example a high frequency (HF) switch, an HF oscillator, a logic circuit and an output transformer. The HF oscillator supplies a high frequency signal for switching the HF switch. The logic circuit supplies a coded signal that is mixed with the switching signal to obtain a signal for controlling the switch corresponding to the coded series of pulses to be emitted. The output transformer enables the series of HF pulses artificially reconstituted to be re-injected into the electricity distribution network.
However, the cost price and overall dimension of such a pulse synthesizer are substantial in the context of the intended applications, which may be a concern of mass markets who demand very low cost prices.
It is well known that the electric line has been used for many years as a low-rate data transmission means, particularly in home automation applications, to remotely control electric appliances (such as electric shutters for example). The known data transmission methods involve injecting, into the network, a carrier signal of higher frequency than the voltage of the network (generally 50 Hz or 60 Hz), which is modulated appropriately to carry data. A disadvantage of these methods is that they require the injection of such a carrier signal. They are therefore intrusive and cause interference.
It is desirable to integrate a pulse synthesizer into a domestic appliance or other commonplace device at the lowest cost and with minimum overall dimension.
Thus, in furtherance of the ideas disclosed by the aforementioned EP 1,136,829, it is desirable to provide a method and a device for emitting high frequency pulses of the same type as those naturally emitted by electric apparatus when they are switched on.
To that end, it is also desirable to cause high frequency spurious pulses to be emitted by an electric element by controlling the production of the spurious pulses using a switch driven by a control signal, instead of seeking to artificially reconstitute such pulses.